Spacer fabrics and methods of making the same

Abstract

In one aspect, methods of making a spacer fabric are described herein. In some embodiments, a method comprises knitting a first yarn or fiber and a second yarn or fiber to form a knit structure, wherein the knit structure comprises a plurality of concave portions in facing opposition to a plurality of convex portions. Further, the concave portions and the convex portions together define void spaces having a substantially double convex cross section. In some cases, the method further comprises heating the knit structure at a temperature sufficient to cause the second yarn or fiber to shrink in at least one dimension. Additionally, the second yarn or fiber shrinks more than the first yarn or fiber during the heating step. Moreover, in some instances, heating the knit structure increases a size of the void spaces of the knit structure, particularly in a thickness direction of the fabric.

1 . A method of making a spacer fabric comprising:
 knitting a first yarn and a second yarn to form a knit structure, wherein the knit structure comprises a plurality of concave portions in facing opposition to a plurality of convex portions, the concave portions and the convex portions defining void spaces having a substantially double convex cross section, and wherein the first yarn is a low thermal shrinkage yarn and the second yarn is a high thermal shrinkage yarn; and   heating the knit structure at a temperature sufficient to cause the second yarn to shrink by at least 10% in at least one dimension,   
       wherein the second yarn shrinks more than the first yarn in the at least one dimension during the step of heating the knit structure. 
     
     
         2 . The method of  claim 1 , wherein the second yarn shrinks by 10-90% in the at least one dimension during the step of heating the knit structure, based on an original size of the second yarn in the at least one dimension prior to the step of heating the knit structure. 
     
     
         3 . The method of  claim 1 , wherein the second yarn shrinks at least two times as much as the first yarn in the at least one dimension during the step of heating the knit structure. 
     
     
         4 . The method of  claim 1 , wherein the step of heating the knit structure increases a size of the void spaces in a thickness direction of the fabric. 
     
     
         5 . The method of  claim 4 , wherein the step of heating the knit structure increases the size of the void spaces in the thickness direction of the fabric by at least 100%. 
     
     
         6 . The method of  claim 1 , wherein the first yarn is a monofilament yarn. 
     
     
         7 . The method of  claim 6 , wherein the first yarn is a monocomponent monofilament yarn or a multi-component monofilament yarn. 
     
     
         8 . The method of  claim 1 , wherein the first yarn has a higher modulus than the second yarn. 
     
     
         9 . The method of  claim 1 , wherein the second yarn is a multifilament yarn. 
     
     
         10 . The method of  claim 9 , wherein the second yarn is a monocomponent multifilament yarn or a multi-component multifilament yarn. 
     
     
         11 . The method of  claim 1 , wherein the knit structure is formed from a third yarn in addition to the first yarn and the second yarn, the third yarn differing from the first yarn and the second yarn. 
     
     
         12 . The method of  claim 11 , wherein the third yarn is a thermally fusible yarn. 
     
     
         13 . The method of  claim 12 , wherein the third yarn is fusible at the temperature of the step of heating the knit structure. 
     
     
         14 - 15 . (canceled) 
     
     
         16 . The method of  claim 1 , wherein the spacer fabric, after heating, comprises a plurality of zones having different compression resistances in a thickness direction of the fabric. 
     
     
         17 . The method of  claim 16 , wherein the spacer fabric has one or more first zones of low compression resistance and one or more second zones of high compression resistance. 
     
     
         18 . The method of  claim 17 , wherein the first zones have a compression resistance of no more than 30 psi and the second zones have a compression resistance of at least 50 psi. 
     
     
         19 - 24 . (canceled) 
     
     
         25 . A spacer fabric comprising:
 a knit structure formed from a first yarn and a second yarn,   wherein the knit structure comprises a plurality of concave portions in facing opposition to a plurality of convex portions, the concave portions and the convex portions defining void spaces having a substantially double convex cross section;   wherein the first yarn is a low thermal shrinkage yarn; and   wherein the second yarn is a high thermal shrinkage yarn.   
     
     
         26 . The fabric of  claim 25 , wherein the knit structure is a unitary knit structure. 
     
     
         27 . The fabric of  claim 25 , wherein the second yarn shrinks at least twice as much as the first yarn in at least one dimension at a heat shrinking temperature between 50° C. and 150° C. 
     
     
         28 . The fabric of  claim 25 , wherein heating the knit structure at a temperature sufficient to cause shrinkage of the second yarn by at least 10% in at least one dimension increases a size of the void spaces in a thickness direction of the fabric. 
     
     
         29 . The fabric of  claim 25 , wherein the fabric, when unheated, is flat or substantially flat. 
     
     
         30 . The fabric of  claim 25 , wherein a thickness of the fabric increases by at least 0.5 cm when the fabric is heated at a temperature sufficient to cause shrinkage of the second yarn by at least 10% in at least one dimension. 
     
     
         31 - 46 . (canceled)